@tante @hypebot So, for previews, absolutely correct. The sending server should generate the preview once; it shouldn't be generated thousands of times on many clients. We should probably be using the `Page` or `Link` types in ActivityPub rather than just including the links and expanding them on the client.
Could you explain the other part? I don't think boosting a post should generate any traffic for the originating server. Is that what happens?